Piston-valve.



No. 696,208. Patented Man 25, I902.

' A. srzucsn.

PISTON VALVE.

(Application filed Dec. 13, 1900.)

(No Model.) 4 Sheets-Sheet 2.

THE Ncnms Prrzns c0.. PHOTO-LITHQ, WASHINGTON n. c.

'No. 696,208. Patentd Mar. 25, I902.

' A. SPENCER.

PISTDN VALVE.

(Application filed Dec. 13, 1900.

' 4 Sheets-Sheet a.

(No Model.

THE NORRIS PETERS co.. PuuTo-umm wAsnlNTuN. n. c.

No. 696,208. Patented Mar. 25, I902.

A. SPENCER.

PISTON VALVE.

(Application filed Dec. 13, 1900.

(No Model.) 4 Sheets$heet 4.

c. 5 4 14' /f J {c c v ZUW'S'QS, 171116772297;

' rue mums PETERS 00v. PHOTGLITHD wnsumavon, n c.

UNITED STATES PATENT CEFICE.

ALEXANDER SPENCER, OF LONDON, ENGLAND.

PISTON-VALVE.

SPECIFICATION forming part of Letters Patent No. 696,208, dated March25, 1902.

Application filed December 13, 1900. Serial No. 39,680. Y (No model.)

To (ZZZ whom it may concern:

Be it known that I, ALEXANDER SPENCER, a subject of the Queen of GreatBritain and Ireland, residing at London, England, have inventedImprovements in and in Connection with Pistons Suitable for Use asPiston- Valves and as Engine, Pump, and Like Pistons, of which thefollowing is a specification.

This invention has reference to an improved and simple construction ofpiston suitable for use as a piston-valve or as an ordinary engine,pump, or like piston whereby a practically fluid-tight joint can bemaintained between the spaces at the respective sides of the pistonwithout the necessity of using tongues or equivalent auxiliary jointingmeans such as have heretofore usually been employed for preventing thepassage of steam or other fluid from one side of the piston to the otherside thereof through the space or spaces ordinarily left between theends of the split packing-ring or between the several parts of asegmental packing-ring on such piston.

The accompanying drawings illustrate, by way of examples, piston-valvessuitable. for use in the valve-chest of a locomotive-engine.

Figure 1 is a longitudinal section; 'Fig. 2, a transverse section on theline a, a, Fig. 1; and Figs. 3 and 4 are detail views hereinafterreferred to. Figs. 5 and 6 are corresponding views to Figs. 1 and 2,respectively, of a modified construction. Figs. 1 and 5 are drawn to asmaller scale than the other figures.

In each of the piston-valves illlustrated there are two compoundpiston-valves of the kind hereinafter described connected by a commonsleeve 1 and fixed upon a valve-spindle 2,

that extends through them and which, though shown arranged eccentricallyto the valves, may be arranged concentrically thereto, if desired. Thetwo connected compound valves are arranged to slide in a liner 3, formedwith parallel annular rows of ports 4 4 4 4 4 4. The ports in eachannular row are separated by straight longitudinally-arrangedbridgepieces 5, and the spaces 7 7 at the two ends of the liner at theouter sides of the two compound valves are in communication with thesteam-supply pipe or passage 8, and the space 9 within the liner andbetween the two compound pistonevalves is in comm unication with theexhaust 10.

Each piston-Valve comprises according to when they are pressed together.

an annular groove 12, the opposite annular side surfaces 13 of which aremade fiat and smooth, and a series of arc-shaped segmental slide-valves14, having the same radius as the valve seat or liner 3, in which theyare to work. The valves 14 are made with slightly inclined or beveledends, as shown in Fig. 4, and with side flanges 15, the outer surfaces16 of which are also made flat and smooth. These slide-valves are fittedin the annular groove 12, so as to bear closely against one or other, orboth, of the opposite annular sides 13 of the said groove, and are madeof such peripheral length that the adjacent inclined or beveled ends ofeach adjacent pair fit practicallyclose against one another, the sum ofthe whole of the spaces between the ends of the several segmentalslidevalves l4 amounting to, say, not more than about oneone-hundred-and-twenty-eighth of an inch. The annular groove 12 and theside flanges 15 are made of such radial depth that a fluidtight jointwill be formed between their ad jacent flat surfaces 13 and 16,respectively,

The segmental slide valves 14 are pressed outward and into close contactwith the valve seat or liner 3 by suitable springs 17, such as coiledsprings, interposed between them and the body of the piston, such actionbeing assisted or not, as may be desired, by steam or other fluid underpressure admitted to the inner side of the slide-valves 14. Theslide-valves 14 are prevented from turning around the piston-body bysuitable means, such as a pin 18, that extends across the groove 12 andpasses through radial slots (see Fig. 3) formed in the opposite flangeson two of the adjacent slide-valves 14 by cutting away the inner endportions of the said flanges. The pin 18 is fixed in the opposite sidewalls of the groove. In this way there is formed a compound piston-valvehaving an annular seriesof slidevalves that not only make a fluid-tightjoint with the piston-body and the Valve seat or liner, in which thecompound valve works, but also with themselves without the aid ofadditional jointing devices.

The bridge-pieces 5 of the valve seat or liner 3 are equal in number tothe inclined or beveled planes of division between the ad jacent ends ofsegmental slide-valves, the adjacent end portions of the saidslide-valves working against the said bridge-pieces when the compoundvalve is moving over the ports.

The segmental slide-valves 14 may conveniently be made from wideinternally-grooved valve-rings,the external peripheries and sides ofwhich are first turned to respectively fit the interior of thecylindrical valve seat or liner 3 and the groove 12. From suchvalverings segments are then cut of such peripheral length that when asuitable number of them are placed together within and around the groovein the piston-body there will be practically no or very little spacebetween theiradjacentinclinedorbeveledends. Gonveniently there may besix segmental slidevalves of an equal peripheral length of practicallysixty degrees each on a grooved piston-body, five of them being cut, asby sawing, from one turned valve-ring of the kind referred to and theremaining one being cut from another similar turned valve-ring.

In the examples illustrated the inn er flanged side of each segmentalslide-valve will, owing to there being a greater steam-pressure in thespaces 7 than in the space 9, be pressed close against the adjacentannular surface of the inner wall of the groove 12 containing suchslide-valve, so as to form a fluid-tight joint therewith, while theadjacent ends of the slide-valves will be so close together as toeffectually prevent the passage of steam be tween them.

Then it is desired that the compound piston-valve shall provide for theready escape of water of condensation from a cylinder through thecylinder-ports controlled by such valve, the latter may be provided witha relief-valve adapted when subjected to sufficient water-pressure toopen and allow 0f the escape of the water from the cylinder through thebody of the piston-valve. One arrangement for this purpose is shown inFigs. 5 and 6, wherein two of the segmental slide-valves let of each ofthe compound piston-valves are each formed at the central portion with ahole 20, that is normally closed by a relief-valve in the form of ahollow cylinder 21, closed at its outer end, which is pressed againstthe perforated portion of the slide -valve by a coiled spring 22,arranged between the said outer end of the cylinder and the body 11 ofthe piston-valve. Instead of two of the valves being provided withrelief-valves one or more than two maybe so provided. The pistonvalvebody is formed on the steam side with one or more relief ports orpassages 23, through which water of condensation can escape into thesteam-chest when the relief valve or valves is or are forced inward bysuch water and through which steam can enter the annular space at theinner side of the slidevalves and assist in forcing them outward againstthe valve-seat against which they work.

A piston having a segmental packing-ring constructed and arranged asdescribed may advantageously be used in the cylinders of engines, pumps,and the like. In this case the pin for preventing rotation of thesegmental slide-valves on the piston-body may sometimes be omitted.

What I claim is- 1. A piston-valve comprising a body portion formed withan annular groove, the opposite side walls of which are fiat and smooth,a series of arc-shaped segmental packing-rings having the same radius asthe valve seat, liner or cylinder in which the piston is to work andmade with slightly inclined or beveled ends and with flanged sides, theouter surfaces of which are also flat and smooth, and springs forpressing the packing-rings outward, the said packin g-rin gs beingfitted in the annular groove in the piston-body so as to bear closelyagainst one or both of the opposite annular sides of the said groove,and being made of such peripheral length that the adjacent ends of eachadjacent pair fit practically close against one another so that apractically fluidtight joint is produced between the packingrings andthe piston-body and between the adjacent packing-rings, substantially asdescribed.

2. In a piston, the combination with the piston-body having a peripheralannular groove, the sides of which are fiat and smooth, of a series ofsegmental packing-rings having flat and smooth sides and formed byturning undivided rings to a diameter to fit the cylinder or liner inwhich the piston is to work, and then dividing the said rings by radialinclined cuts into segments and arranging within the said groove anumber of these segments of such peripheral length as will cause theiradjacent ends to come into close contact with one another and producepractically fluidtight joints between them and form a segmental ring ofthe same diameter as that of each of the undivided rings from which thesegments are cut, as set forth.

3. In a piston-valve, the combination with the piston-body having aperipheral annular groove, the sides of which are flat and smooth, of aseries of segmental packing-rings having flat and smooth sides, awater-relief port in one of said segmental packing-rings normally closedby a spring-actuated relief -valve, a drain -passage in the piston-bodythrough which water that enters the piston body through saidrelief-valve can drain away, so that when the piston is used as asteam-distributing valve in a cylinder it will allow of the escapethrough itself of condensed water as set forth.

Signed at 77 Cannon street, in the city of London, England, this 28thday of November, 1900.

ALEXANDER SPENCER.

\Vitnesses:

RICHARD THOMSON GLASCODINE, H. BIsnoP.

